java/feathub-udf/flink-udf/src/test/java/com/alibaba/feathub/flink/udf/aggregation/CountAggFuncTest.java
<reponame>alibaba/feathub<filename>java/feathub-udf/flink-udf/src/test/java/com/alibaba/feathub/flink/udf/aggregation/CountAggFuncTest.java/*
 * Copyright 2022 The FeatHub Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.alibaba.feathub.flink.udf.aggregation;

import org.junit.jupiter.api.Test;

import static org.assertj.core.api.Assertions.assertThat;

/** Test for {@link CountAggFunc}. */
class CountAggFuncTest {
    @Test
    void testCountAggregationFunction() {
        final CountAggFunc aggFunc = new CountAggFunc();
        CountAggFunc.CountAccumulator accumulator = aggFunc.createAccumulator();
        assertThat(aggFunc.getResult(accumulator)).isEqualTo(0);
        aggFunc.add(accumulator, 1L, 0);
        CountAggFunc.CountAccumulator accumulator2 = new CountAggFunc.CountAccumulator();
        accumulator2.cnt = 2L;
        aggFunc.merge(accumulator, accumulator2);
        assertThat(aggFunc.getResult(accumulator)).isEqualTo(3);
        aggFunc.retract(accumulator, 1L);
        assertThat(aggFunc.getResult(accumulator)).isEqualTo(2);
    }
}
